The present invention relates to an improved camera in which the shutter mechanism can be released either by an electromagnetic release device or by a mechanical release device in response to the depression of a common manual member.
A camera of the above type is described in U.S. Pat. No. 3,955,209 and includes a release member urged from a locked position to a rest position and adapted to release the shutter mechanism for an exposure when moved to the second position, and first and second locking mechanisms for locking the release member at its locked position respectively. The first locking mechanism is disabled by depression of the shutter button while the second locking mechanism is disabled when an electromagnet is excited in response to the depression of the shutter button or when a shutter dial is set for mechanical exposure control. Moreover, when the shutter dial is set for electric exposure control, depression of the shutter button causes the first locking mechanism to be disabled and at the same time causes excitation of the electromagnet to disable the second locking mechanism, thereby allowing the release of the shutter mechanism. On the contrary, when the shutter dial is set for mechanical exposure control, depression of the shutter button causes the first locking mechanism to be disabled, thereby allowing the release of the shutter mechanism since the second locking mechanism has been disabled by the setting of the shutter dial prior to the depression of the shutter button.
As is well known, as compared with a mechanical release device, an electromagnetic release device has general benefits in that it is only necessary for excitation of an electromagnet, i.e., for release of a shutter mechanism, to open or close a switch by depression of a shutter button, so that only a small force is required for the depression of the shutter button and that a stroke of the required depression is shortened. These benefits result in a reduced likelihood of blurring of the picture being taken. However, the above camera described in U.S. Pat. No. 3,955,209 does not enjoy such benefits of electromagnetic release because, even for electromagnetic release of the shutter mechanism, the shutter button must be depressed with the same stroke and force to disable the first locking mechanism.